ANR MARCARA

International collaborative research project (ANR PRCI) with the Alfred Wegener Institute in Bremerhaven (Helmholtz Centre) on the variability of the radiocarbon age of the marine reservoir and its implications for palaeoceanography, palaeoclimatology and geochronology.

The 14C age of the marine surface reservoir (MRS) is a tracer of air-sea gas exchange and carbon mixing in the ocean. These processes are linked to climate, ocean and carbon cycle parameters that have varied over the last 50,000 years.

The MARCARA project focuses on the observation and numerical modelling of MRA for key sites in the main oceans. We are measuring 14C ages on micro-samples using the AixMICADAS spectrometer equipped with its multi-purpose ion source (solid & gas). This allows us to better quantify the MRA and avoid, or correct, certain biases.

Our German partners are using numerical models based on a high-resolution unstructured mesh approach to zoom in on the regions of interest, with assimilation of marine and atmospheric 14C data.

The MARCARA project focuses on the last deglaciation and abrupt climate changes such as the Heinrich and Dansgaard-Oeschger events, whose role in the carbon cycle is still poorly understood.